Dr. Jarrod Hardke & Dr. Bob Scott
March 24, 2017 No. 2017-02 www.uaex.edu/rice
Of March Rice and Men
Rice season 2017 is a go for Arkansas. The first confirmed rice in the ground happened in south Arkansas on 3/18. Many more have gotten underway this week up and down the state. Fingers crossed for a better year than last.
The long term forecast shows upper 60s to lower 70s and lots of rain chances starting tonight (3/24). So a short burst looks like all there is to be had for now – which may be a good thing. To throw a rock at a number, I guess we may be 5% planted by the time the rain arrives starting tonight.
Do it Right, Do it Light; Do it Wrong, Do it Long
I’m sure everyone has heard that line in sports somewhere growing up. Bottom line works the same for planting rice. Margins are thin and seed supplies are tight, so there’s not a lot of room for error.
Plant varieties first. Seriously. One of the big advantages of hybrid rice is that it holds a high percentage of its optimum yield into later planting dates on average compared to varieties. Add in the fact that hybrid seed supplies are tight – plant a little too early and get a bad stand and it’s doubtful there’s seed for a replant.
Whatever your mix of hybrid versus varieties, plant the varieties first. The higher seeding rates used and generally better cold tolerance will reduce risk of severe stand loss.
If only varieties are in the mix, save the ones with the best disease packages for later. Disease pressure generally increases as we delay planting.
If only hybrids are in the mix, plant the ones you’re most comfortable with first. Don’t skimp on early seeding rates either. Save any hybrids that are new to you for later plantings when you’ll get the best response.
Seeding Rate Recommendations
The RICESEED program up to date and can be accessed here: https://riceseed.uaex.edu/. The PDF of RICESEED recommendations is here: https://www.uaex.edu/farm-ranch/crops-commercial‑horticulture/rice/Riceseed%20Update%202017.pdf. Pay close attention to the fact that 2016 growing conditions had an impact on seed size and that you may need to increase your seeding rate to compensate.
Seed Treatments – What’s In Them?
Table 1 provides a breakdown of whether specific seed treatment products contain an insecticide, fungicides, or both. Keep in mind that the insecticides don’t control the same insects equally and the fungicides don’t control the same seedling diseases equally. Choose wisely! Hybrid rice seed already has a fungicide package so you just need to add an insecticide, but some are available with both an insecticide and fungicides – KNOW WHAT’S ON THE SEED BEFORE YOU PLANT! A few were caught last year thinking seed was treated with things it wasn’t!
Table 1. Seed treatment products for rice and description of use.
2017 Weed Control
Overlapping residual herbicides was the key to success for many growers in AR last season. This usually involved starting with Command or Command plus League or Facet up front and then coming back with more Command or Prowl H2O and kicking in a POST herbicide where needed. This did not address ALS-resistant sedge acres and most of those acres starting off with a mixture of Bolero and propanil with a residual of some kind early POST or RiceBeaux mixed with Prowl delayed PRE/EPOST.
The point is an effort was made to either never let the grass emerge (preferred!) or to get the first treatment out while grass and sedge was extremely small. There are a number of new compounds slated for availability in 2018, notably Rogue or Rogue Plus, Loyant, and maybe some Provisia rice, while I expect both of these to be game changers they will not be here in time to help in 2017. So, my advice is to stay the course this year and hopefully we will have good moisture early again for activation and be successful with the overlapping PRE concept.
One new premix will be on the market in 2018. RiceOne CS from RiceCo is a mixture of clomazone and pendimethalin. This could fit nicely into a residual heavy or overlapping PRE program. There is an aerial label for Arkansas. For heavier soils you may need to add Command to reach the maximum rate of 1.6 points or 25.6 oz/acre or stay at 2.1 pint (33.6 oz) rate of Prowl H2O. The rate range on the label is from 24-50 fluid oz/A (Table 2).
Table 2. Rate equivalencies of RiceOne CS to Command 3ME, Prowl H2O, and Prowl 3.3EC in fluid oz per acre.
What to Do About Zinc?
On soils with pH over 6.0, it is recommended to apply granular Zn at 10 lbs of actual Zn per acre when soil test values are below 4 ppm. This recommendation is partly due to the lack of mobility of Zn in the soil after application (it sits where it hits). This application allows for adequate plant-available Zn across the field and builds soil Zn levels.
Zn seed treatments alone are not enough to combat low Zn soils, but provide insurance. In some instances where soil-test Zn levels are marginal, the use of a Zn seed treatment and a granular Zn product with a low rate but uniform distribution may be adequate to prevent deficiencies, but should be used with care. With low soil test Zn levels it’s usually found to be much cheaper to put out 10 lbs Zn per acre than to risk other methods and still end up fighting a deficiency.
When using Zn seed treatments the recommended rate range is 0.25-0.5 lb Zn per 100 lb of seed (cwt). Do not exceed the 0.5 lb Zn/cwt rate or you can experience negative growth effects.
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This information will also be posted to the Arkansas Row Crops blog (http://www.arkansas-crops.com/) where additional information from Extension specialists can be found.
More information on rice production, including access to all publications and reports, can be found at http://www.uaex.edu/rice.
We sincerely appreciate the support for this publication provided by the rice farmers of Arkansas and administered by the Arkansas Rice Research and Promotion Board.
The authors greatly appreciate the feedback and contributions of all growers, county agents, consultants, and rice industry stakeholders.